According to this piece, the Middle Ages experienced a warmer period than today, even with our current global warming trend. From the article:
A review of more than 240 scientific studies has shown that today’s temperatures are neither the warmest over the past millennium, nor are they producing the most extreme weather – in stark contrast to the claims of the environmentalists.
The review, carried out by a team from Harvard University, examined the findings of studies of so-called “temperature proxies” such as tree rings, ice cores and historical accounts which allow scientists to estimate temperatures prevailing at sites around the world.
The findings prove that the world experienced a Medieval Warm Period between the ninth and 14th centuries with global temperatures significantly higher even than today.
They also confirm claims that a Little Ice Age set in around 1300, during which the world cooled dramatically. Since 1900, the world has begun to warm up again – but has still to reach the balmy temperatures of the Middle Ages.
The timing of the end of the Little Ice Age is especially significant, as it implies that the records used by climate scientists date from a time when the Earth was relatively cold, thereby exaggerating the significance of today’s temperature rise.
I’m not surprised by these findings. Like many people I’m deeply concerned about sustaining ecological balance and preserving biodiversity. However the scientist in me has always doubted the histrionics of environmentalist who freak out and claim that this global warming trend spells ecological disaster by the end of the century. My reasoning is simple: The earth’s climate has experienced radical temperature fluctuations that dwarf the mild increases we’ve seen in the last 150 years. The overall solar radiation alone has increased by 30%, and yet we are still here basking in relative balmy conditions. I’m not saying industrial pollution isn’t contributing to global warming – it is. Only that the our small contribution is insignificant in the geological scheme of things. In the last 4 billion years, the earth’s biosphere has experienced and survived at least 5 extinction level events, in addition to enormous tectonic shifting, single volcanic eruptions larger than all previous eruptions in history and massive solar radiation spikes. As George Carlin says, “the Earth doesn’t need saving, we do”.
I am confident however that sufficient intelligence will rise to the task to ensure that it continues beyond the womb planet.